While it’s hard to predict whether stock or bond prices will go up or down in the short term, it’s possible to foresee movements over periods of three years or longer, the academy said.

“These findings, which might seem surprising and contradictory, were made and analyzed by this year’s laureates,” the academy said.

Fama, 74, and Hansen, 60, are associated with the University of Chicago. Shiller, 67, is a professor at Yale University.

American researchers have dominated the economics awards in recent years; the last time there was no American among the winners was in 1999.

The Nobel committees have now announced all six of the annual $1.2 million awards for 2013.

The economics award is not a Nobel Prize in the same sense as the medicine, chemistry, physics, literature and peace prizes, which were created by Swedish industrialist Alfred Nobel in 1895. Sweden’s central bank added the economics prize in 1968 as a memorial to Nobel.